This invention relates to document sorting devices and more specifically to multiple pass document sorting devices.
Document sorting devices are beneficial to any business in which a large number of documents must be sorted and processed. Documents are deposited upon an input holder and sorted to a plurality of output holders. Since a large number of documents are involved, for a complete sort it would be necessary to provide one output holder for each document or one output holder for each group of documents.
Space and cost limitations dictate a relatively small number of output holders regardless of the number of documents to be sorted. Because of this, in order to achieve proper sorting of a large number of documents when a relatively small number of output holders exist, it is necessary to execute multiple sorting passes. In this manner, after a specified number of sorting passes, documents will be deposited within the output holders in the desired sequence.
A mail-sorting machine capable of multiple pass document sorting is described in U.S. Pat. No. 4,275,875 entitled "Mail Sorting Machine" by Roy Akers and is incorporate herein by reference for the purpose of illustrating the state of the prior art. After a single sorting pass, the documents deposited within the output holders must be removed and deposited into the input holder. This must be done before subsequent sorting passes may be initiated since output holders must be empty to receive the next pass of newly sorted documents. Furthermore, documents are physically carried from the output holders to the input holder.
It is an object of this invention to provide a multiple pass document sorting device in which the sorting throughput may be maximized by permitting a sort to be initiated without the need to transfer every document cluster to the input holder before a next sorting pass may be initiated.
It is another object of this invention to eliminate the need for manually carrying document clusters from the output holders to the input holder.
It is furthermore an object of this invention to automate the process of transferring document clusters from the output holders to the input holder.